Juvenile court histories were investigated of male and female juvenile drug offenders and of control groups of juvenile delinquents never charged with drug-related offences. On most of the parameters of drug-related and of other criminal offences, criminal involvement was greatest among opiate abusers, followed by those abusing sedatives, and then by cannabis abusers. However, this difference was less marked among females than among males. Involvement with crime not related to drugs was greater among delinquents abusing opiates and sedatives than among delinquent controls, while the criminality of delinquents abusing cannabis was less than that of the controls. There were significant differences between the patterns of offences of the four groups, which did not support the economic necessity hypothesis of crime among (at least juvenile) drug abusers. The findings were consistent with progression from soft to hard drugs, and with the view that where juvenile delinquency and drug abuse co-exist, the former tends to precede the latter. The association between juvenile drug abuse and delinquency seems to be accounted for by a common denominator of a sociopathic character development, rather than by some form of causal relationship between these two phenomena.